Flickr has added more real-time goodness to their photo API. Using a publish / subscribe (PubSub) system, developers can now receive real-time updates across millions of photos across Flickr friends, Flickr Commons, and by tags and geo-location using the Flickr Real-Time API.

Google has released version 3.0 of the YouTube Data API which includes new functionality and features including Topics API, Universal Search, Channel Bulletin Post, Full Subscriber List Management, and more.